Dirigible bomb



Jan. 24, 1950 R. D. WYCKOFF ETAL 2,495,304

DIRIGIBLE BOMB Filed May 31, 1946 5 Sheets-Sheet 2 AUDI o OscILLFS-TORHil RADIO TRANSMITTER 40 'RHDIO iflig. 6 RECEIVERA? ELEJVATOR N k RUBBERsac/r us'ron BC'IUH'IOR V EIWMMS RALPfI D. WYCKOFF JBMES W. FITZWILL 1AMJan. 24, 1950 R. D. WYCKOFF ETAL DIRIGIBLE BOMB 5 Sheets-Sheet 3 FiledMay 31, 1946 3mm! RPSLPH D. WYCKOFF ME FIT'ZWILLIEM DAN "r32 SALVJSTTI OwAUHvA Q0 GE a amnflzoo mmmHamWmZom PM W DIRIGIBLE BOMB Filed May 31,1946 5 Sheets-Sheet 4 E umcaeme SOLEZNOID Rrrcaaomz RIGHT in/um;

RALPH D. WYCK OFF JAMES w. FITZWILLIEM DBNTE SALVETTI Jan. 24, 1950 R.D. WYCKOFF ETAL DIRIGIBLE BOMB 5 Sheets-Sheet 5 Filed May 31, 1946Patented Jan. 24, 1950 T D srras PATEN was DIRIGIBLE BOMB corporation ofDelaware Application May 31, 194.6, Serial No. 073,372

11 Claims.

1 This invention relates to dirigible bombs and particularly to aremotely controlled high-angle bomb having a relatively steep trajectorybearing a general similarity to that of a freely falling bomb asdistinguished from gliding bombs, for example, which approach the targetat a low angle.

In order efiectively to accomplish military bombing from aircraft, it isnecessary to have a high percentage of target hits. Numerous aimingtechniques have been employed to improve bombing accuracy, and at thepresent time this has reached a fairly high state of development. When abomb is dropped so as to fall freelyfrom the bombing plane, variousfactors are known to affect its trajectory. The magnitudes of theseeffects have been carefully determined and are customarily taken intoconsideration by the bombardier or by the automatic mechanism of hisaiming apparatus or bomb-sight.

Freely falling bombs are customarily aimed by dropping them at anopportune moment which is indicated by a so-called bomb-sight.bomb-sights make corrections for such factors as altitude of the plane,wind velocity, plane velocity, etc. However, in spite of carefulconsideration of the known factors involved, a certain amount ofscattering occurs due to uncontrollable effects. Some of these effectsare aerodynamic, some mechanical, some atmospheric.

It has been found desirable to steer an otherwise freely falling bomb soas to correct for inaccuracies in aiming and to correct forunforeseeable effects encountered by the bomb in flight. In spite of therelatively high terminal velocities attained by high-angle bombs, wehave found that aerodynamic steering of a bomb i flight is both feasibleand effective. Bombing accuracy has thereby been improved at leastten-fold.

This invention concerns a steerable bomb remotely controlled from thebombing plane by radio.

In the making of a steerable high-angle bomb, a number of factors mustbe taken into account. Means for producing deflecting or lift forcesmust be added in the form of aerodynamic surfaces. In addition, steeringsurfaces must be provided to maintain the desired angle of attackrequired for the production of deflecting forces. In order that steeringcontrols be unambiguous, it is necessary to stabilize the bomb andcontrol the space orientation of reference axes thereon. Dynamicstability in flight must be maintained to avoid undue oscillations andgyratlons of the bomb. In addition, a number of practical con- These .2siderations are involved; namely, structural strength must be sufficientto handle the aerodynamic forces required and space requirements shouldbe kept within that permitted on military aircraft.

Strategic military requirements dictate a number of factors in theaerodynamic design of controland steering surfaces of a dirigible bomb.These concern principally maneuverability and accuracy. It has beenfound that a 1000-pound a ground area approximately 1,500 feet inradius.

It must, of course, be capable of being accurately guided to the desiredtarget within this area, such accuracy being as high as possible. Theabove maneuverability necessitates the use of aerodynamic surfaces whichdevelop enough lift forces to produce the required path deflection; thatis, it determines the aerodynamic lift that the bomb must generate whenyawed at a preferred maximum trim angle with respect to its line offlight.

On the other hand, practical military requirements dictate factors whichare not all compatible with the above aerodynamic requirements. Spaceavailable on military aircraft is limited and the bomb must be carriedin the internal bomb bays of standard bombing planes. Furthermore, thefins and controlling mechanism should desirably be capable of attachmentto standard bomb cases. It is obviously also desirable to make thecontrol device as simple and inexpensive as more important requirementspermit, These and other considerations have been so balanced in theembodiment of our invention that an operable device having manypractical advantages is obtained.

It is an object of this invention to provide a remotely controlledhigh-angle bomb.

Another object is to provide a high-angle bomb having improved stabilityin flight.

Another object is to provide a unitary twocomponent control surfacestructure which may be readily attached to standard bombs for enablingthe latter to be remotely steered in both azimuth and range.

Another object is to provide a two-component steerable bomb in which thecontrol surfaces are disposed in spaced symmetrical relation about thebomb axis.

Another object is to provide a remotely controlled high-angle bomb inwhich the control surface supports form leading edges for rollstabilizing ailerons.

Another object is to provide a bomb having a novel and advantageousaileron operating mechanism.

Another object is to provide a bomb having an auxiliary aerodynamic liftsurface in advance of the control surface for increasing the effect ofthe latter upon the course of the bomb but which may be removed withoutappreciable change in trim yaw or pitch angle if the additionalmaneuverability due to the auxiliary surface is not required.

Another object is to provide a bomb having staggered shroud supports toimprove roll stability.

These and other objects of the invention are attained by means of a tailstructure having cylindrical symmetry and whose cylindrical liftsurfaces are equipped with rudders and elevators remotely controlled bymeans of radio, the supports for such lift surfaces being equipped withailerons which are gyro controlled to prevent roll.

Details of the invention are described in the following specification,of which the drawings form a part and in which Fig. 1 is a side view ofthe dirigible bomb forming the subject of this invention;

Fig. 2 is a side view of the invention showing the tail structure insection;

Fig. 3 is a rear view of our bomb showing the means for controllingrudders and elevators;

Fig. 4 is a block diagram of the radio transmitting apparatus on theplane for controlling the course of the bomb;

Fig. 5 is a block diagram of the radio apparatus in the bomb responsiveto the radio control signals;

Fig. 6 is a schematic electrical wiring diagram of the control apparatuson the bomb;

Fig. 7 is a schematic electrical wiring diagram of the gyro aileroncontrol mechanism;

Fig. 8 is a schematic electrical wiring diagram of the radio relaycircuit; and

Fig. 9 is a schematic electrical wiring diagram of a rudder or elevatoractuating servo-mechanism.

Referring to Fig. 1, Ill represents the body or war head of a dirigiblebomb. The case of the war head In and its explosive charge may be of anyknown type. A fuze mechanism II may be either contact or time controlledin known manner. Arming device I2 may be -of known anemometer type oralternatively the bomb may be armed mechanically as it leaves the plane.A tall structure I3 is fastened to the end of the war head In andattached thereto are shrouds or control surfaces to be described. At theend of the tail structure I3 is attached a flare I4 usually started by adelayed action time fuse 'as it leaves the plane. The purpose of thisflare is to permit the bombardier to easily observe the course of thebomb after it has left the plane. Tail structure I3 also contains radiocontrol equipment for operating the rudders and elevators, such controlequipment having exposed antenna I5. Ailerons may be operated by meansof automatic equipment also housed in tail I 3. The operation of thesevarious components will be explained in detail later.

Inasmuch as war head I0, fuze II, arming device I2, and flare I 4 areknown devices, they will be omitted in discussion oi? subsequentfigures.

Referring to Fig. 2, tall structure I3 is shown in section in order tomore clearly illustrate the manner of operating ailerons and elevators.Fig.

" are used forward of the tail surfaces.

' entitled 3 is a rear view of the tall with the rear cover and flareremoved. Radial supports I6 (Fig. 2) at the forward end of the tailstructure support a cylindrical aerodynamic surface I1 whose functionwill be explained later. A second set of radial supports I8 supportaerodynamic surface I9 and attached steering means. Mounted on thetrailing edge of supports I8 are ailerons 20 pivoted on a radial torquerod 2| which passes through the interior of support I8. Fastened to eachaileron operating rod 2I is a crank arm 22. Crank arms '22 may bebifurcated at their outer end and engage a radial pin 23 carried on anangle bracket 23a welded to a circular plate 24 pivoted at 25 on theaxis of the bomb. Thus, plate 24 mechanically ties all four aileronstogether and at the same time rotation of plate 24 operates all aileronssimultaneously to cause rotation in the same direction about the axis ofthe bomb. Eccentric to the axis of plate 24 a rocker arm 26 engagesplate 24 through ball and socket joint 21. Rocker arm 26 maybe supportedat bearing 50. The other end of the rocker arm engages the armature of apair of opposed solenoids 28 so that deflection of plate 24 may beobtained, either clockwise or counterclockwise. The electric current insolenoids 28 is controlled by means of electric contacts mounted on agyro mechanism housed in tail structure I3 such that upon rotation ofthe bomb about its axis, tilt of the gyro unit actuates the contactwhich energizes the appropriate one of solenoids 28 to cause properdeflection of the ailerons to restore roll orientation. Sucha gyro unitis described in co-pending application Serial No. 543,168 by Molnar andCarnvale entitled Gyro bomb stabilizer, and its operation will bedescribed more fully later.

Under certain conditions, aerodynamic forces may act on the bomb whichrequire considerable aileron effect to prevent rotation. Furthermore, inorder to avoid increasing the size and capacity of aileron operatingmechanism, the efllciency of aileron action should be maintained as highas possible. It is known that by providing ailerons with a leadingsurface, the aerodynamic efliciency of the ailerons is materiallyincreased. Advantage is taken of this fact in our invention by makingthe radial supports I8 simultaneously also provide an effective leadingsurface ahead of the ailerons 20 to augment their lift or aileroneffect. We have found that it is desirable to place the ailerons as farback in the stabilizer tail as possible. Ailerons ahead of thestabilizer lift surfaces may still serve as such but produce a backwashwhich impinges on the tail surface and causes an undesirable oscillationof the bomb. This is especially true when only a pair of ailerons In ourpreferred embodiment four ailerons are used and mounted on the trailingedge of the radial struts used to support the rear cylindrical liftsurfaces. However, two ailerons may be used if sufiicient aileronsurface is provided.

In a co-pending application, Serial No. 673,373, filed of even dateherewith, by Ralph D. Wyckoif Aerodynamic surface for dirigible bomb,"the advantages of substantially cylindrical control surfaces I1 and I9are brought out. Inasmuch as radial supports I 6 and III for the controlsurfaces I I and I9, respectively, represent non-cylindrical structure,there is an opportunity for the development of small rotational forces.These rotational forces may be materially reduced by staggering therotational position of supports I6 and I8 about the axis of the bomb.Thus one may use four supports i8. 90 degrees apart, each having anaileron and use four supports I6, also 90 degrees apart, but staggered45 degrees with respect to the position of supports Hi.

When the bomb is in flight and movingin the wind stream in an attitudesuch as to give aerodynamic surface IS an angle of attack, the surface[9 produces lift'forces at right angles to the wind stream tending todeflect the path of the bomb. We have found that the addition ofaerodynamic surface I! augments the effectiveness of the surface inproviding lift such that the maneuverability is materially increased. Byproper location of the surfaces I1 and I9 with respect to the center ofgravity of the bomb, one may alternatively remove surface I! withoutappreciable change in the available trim yaw angle. This results in areduction in maneuverability to about 60 per cent that of the doubleshroud arrangement, but under certain conditions this is permissible andthe reduction in space required at the tail end of the bomb is ofttimesa compensating advantage. In the disposition of control surfaces on ourbomb, the ability to add or subtract lift shroud l1 according toconvenience without materially changing the aerodynamic stability of thebomb is an important advantage.

The proper trim angle of the control surface I9 is attained through theuse of elevators 29 and rudders 30 (Fig. 1). These are hinged at 3| and32 (Fig. 1), respectively.

The design of the aerodynamic surfaces l1 and I9 and of the steeringsurfaces 29 and 30 as well as of the ailerons 20, is governed by themilitary requirements previously stated. In view of these requirements,the most significant factors in the design of a high angle bomb are:

1. The lift-at-trim, or the lift that the bomb can generate at apreferred maximum trim pitch or yaw angle.

2. The roll torque suffered by the bomb when it is at a trim angle ofattack caused by simultaneous deflection of the rudders and theelevators.

3. The weather-cock stability of the bomb over the range of pitch and/oryaw angle through which the bomb moves. One of the variables affectingthe period of yaw or pitch osci11ations is the stability, and thestability is the only quantity over which the designer has a largemeasure of control in the event he wishes to modify the period ofoscillation.

. The speed at which the rudders and elevators move when the bomb isbeing controlled in flight.

5. The size, shape and disposition of the aerodynamic surfaces.

Higher maneuverabflities or higher lifts-attrim can be achieved bylarger aerodynamic surfaces and/or by lower stabilities, whereasaccurate steerin when correcting small errors with simple On-01f controlcan best be done on a bomb of low maneuverability and high stability.Simple theory and wind tunnel tests show that the lift-at-trim ofhigh-angle bombs increases with size of the aerodynamic surfaces, butdecreases with increase in stability. With' On- Ofi control, a lowmaneuverability permits small corrections to be made accurately and highstability permits the use of fast-moving rudders and elevators withoutthe danger of large induced pitch and yaw oscillations and theconsequent large roll torques.

control application quickly when the bomb is heading toward the target.Field experience has indicated that reasonably accurate steering can bedone if the rudders and elevators move from the undeflectedposition tothe deflected position in from 0.5 sec. to 2.0 secs, although moreaccurate steering can be done if the controls move even more rapidly.However, the speed of motion of the control surfaces affects themagnitudes of the pitch and yaw oscillations of the bomb, and to keepthese amplitudes small it is necessary that the length of time it takesfor the elevators or rudders to move from the undeflected position tothe deflected position be approximately equal to or greater than theperiod of oscillation of the bomb in the latter part of its flight.Thus, the stability of the bomb must be adjusted to produce this period,a preferred range of values of which is from 0.3 sec. to 2 sees. for theperiod of oscillation.

Furthermore, field experiments have indicated that in the correction oflarge errors more accurate steering can be done if there is availablemore maneuverability than is necessary to barely correct 100-mill errorsby steady and continuous application of control. This extramaneuverability is needed because the error to be corrected is noteasily detected immediately after release, hence the operator must waitfor about 10 or 15 seconds after release, at which time the aiming errorbecomes apparent, before he can intelligently direct the bomb. Thus, themaneuverability available in the first 10 seconds of flight is generallywasted. In addition, it is conducive to accurate steering to be able toguide the bomb so that it is headed for the target well before impact.Under this condition, since the aiming error is corrected before impact,it is apto be able to correct by steady application of f control, errorswhose mil value is two or three,

L=lift force in lbs.

q= V='=dynamic pressure of wind stream in lbs., p being the air densityin slugs/ft. and V being the velocity in ft.

A=circular cross-sectional area of bomb body in ft? In 1000-lb. bombswith large cylindrical tail cans (I3Figs. 1 and 2), and in order toobtain a stability great enough to produce periods of oscillation ofapproximately one second, it is necessary that the diameter of the liftand control octagons be greater than the diameter of the bomb body. Ingeneral, the greater the ring diameter, the greater the aerodynamic liftand stability. The maximum diameter of shroud ring is fixed by thedimensions of the bomb bay in which it will be carried. Spacelimitations in standard bomb bays, convenience in attaching the tails tothe bombs in the bomb bay, and convenience in shipping the tail units totheaters 7 of combat make it desirable that the forward lift shroud I!be attached to the tall cylinder I3, rather than to the war head ID. atthe same time making the tall as compact as possible. The length,diameter, and position of the forward lift surface I! may be adjusted toproduce a lift coefficient which lies between 0.4 and 2.0 for a trimpitch or yaw angle of about We have found that the combination of thetwo surfaces results in a stability great enough to keep the period ofpitch or yaw oscillation below one second during the latter portion ofthe flight. Further, the size and position of the two surfaces may be soadjusted that the stability and the controllability (defined by the trimyaw angle versus rudder angle relationship), remain approximately thesame when the forward surface is removed. Thus, the only significantchange in the bomb characteristics that is caused by the removal of theforward surface I! is a lowering of the bomb lift-at-trim affecting itsmaneuverability. Without the forward lift surface the bomb may beadvantageously used where large error corrections do not have to bemade.

We have found that the above aerodynamic characteristics may be attainedby making either tail shroud length less than per cent of the bomblength. The shroud length is defined as the dimension parallel to theaxis of the bomb, this being the dimension which is commonly called thechord. The bomb length as here used includes the tail structure. We havefurther found that the sum of the chord lengths of the two tail shroudsshould not exceed 50 per cent of the bomb length.

The use of two shrouds separated by an air gap as shown in Figs. 1 and 2has been found to result in better aileron control and more effectiveroll stabilization. The two shrouds need not be of equal size. The spacebetween the shrouds permits air flow by the ailerons which otherwise maybe shielded. We have found that the space between the two tail shroudsshould be greater than 10 per cent of the chord length of the smallershroud.

In order to obtain effective steering of the bomb and to develop thetrim angle of attack, it is necessary to keep within limits in therelation between flap area, flap deflection, and shroud area. We havefound that for one component, the product of the total flap area in percent of total shroud area by the maximum available flap deflection indegrees, should lie between and 325 in order to attain the advantageousaerodynamic characteristics previously mentioned. A similar relationshipapplies to the ailerons. We have found that the total aileron movingarea in per cent of the total shroud area multiplied by the maximumaileron deflection in degrees should lie between 20 and 200 in order toattain satisfactory roll stability. 1

In Fig. 3 we have shown an end view of the rear control surface l9 so asto illustrate the manner of operating rudders 29 and elevators 30. Eachof the flaps 29 and 30 may have welded thereon asmall angle bracket 32.Operating rods 33, 33', 34, 34' are hinged at the brackets 32 and extendfrom the flap inward to operating mechanism inside the tail l3. At theinner end rods 33 and 33' are engaged by a crank pin 36 mounted on theend of a crank arm 31 driven by means of servomotor 38. Servomotor 38,for actuating the elevators, is mounted somewhat off-center in order togive room for a similar servomotor 39 for actuating rods 34 and 34' tothe rudders 30.

Rods 33' and 34' may be of rectangular section and twisted through 90degrees at the region where they cross in order to provide clearancebetween them. Thus, by proper control of servomotors 38 and 39, it ispossible to actuate both of the elevators 29 or both of the rudders 30in the same direction in order to bring lift surfaces I1 and I9 into theproper trim angle for providing the necessary path deflecting forces,these forces being set up through the operation of wellknown aerodynamicprinciples.

Fig. 4 is a block diagram of the radio transmitting equipment carried inthe bombing plane and for steering the bomb in its course by means ofradio signals. The bombardier in the plane may observe the course of thebomb and from such observation easily determine the deviation requiredto bring the bomb on target. Signals are transmitted by radio fromconventional transmitter having a conventional antenna 4| on the plane.Various known methods'of transmitting the necessary signals over such aradio channel may be used, and the one here described is by way ofexample. Four audio-oscillators Fu, Fa, Fr, F1 are provided, eachmodulating the radio transmitter 40 at a characteristic audio-frequencywhen its respective key is pressed. Thus, the bombardier has availablefour push buttons 42, 43, '44, and 45. If the bomb requires deviation tothe right, he may push button 44, which causes oscillator Fr to modulatetransmitter 40 at a predetermined frequency. The other oscillatorsoperate at different audio-frequencies, each being controlled by itsrespective push button. The controlling radio wave, therefore, comprisesa carrier frequency modulated by an audio-frequency appropriate to thedirection of deviation which the bombardier desires to impart to thebomb. The four push buttons 42, 43, 44, 45 may be combined on asingle-control stick as of the so-called joy stick variety. The radiocircuits may be so arranged that both azimuth and range control may beapplied simultaneously, the transmitter in this case being modulated bytwo audiofrequencies simultaneously and transmitting both of these tothe bomb.

Fig. 5 is a block diagram of the radio receiving equipment carried inthe bomb and used for responding to the steering signals from the plane.Here 46 represents the antenna, shown in Fig. 1 by numeral l5. Connectedthereto is conventional radio receiver 41, including a demodulator whichdelivers audio signal to four fllters, R, L, U, D. These are narrow bandpass filters of known type and when an appropriate signal is received,it is passed on to rudder actuator 39 or elevator actuator 38 which inturn deflects the rudders or elevators in the proper sense. The type ofcontrol here described by way of example, is a simple On-Ofi type. Inthe absence of audio modulation of the radio signal received by 41, therudder and elevator actuators return to neutral.

In the above embodiment of the radio control. if, for example, thebombardier desires to apply left rudder, he may close contact 45, Fig.4, and thereby modulate the radio signal at a frequency FL. The receiver41 picks up this signal, and passes on a frequency F1. to the filters R,L, U, D. As this frequency may only pass through filter L, there isapplied to the rudder actuator 39 a signal which causes the rudders 30to move to their extreme left position. If none of the contacts 42, 43,44, 45 are closed by the bombardier, no signal passes the filters D, U,L or R and the rudder and aeeasos elevator actuators automaticallyreturn to their neutral position by a control to be described later.This method of controlling the steering of the bomb has been foundhighly satisfactory, but alternatively other control channels or the useof so-called proportional controls may be devised by those skilled inthe control art.

The bomb control apparatus will be now described with reference to Figs.6, "I, 8 and 9 which are schematic wiring diagrams of the variouscomponents involved. 7

Referring to Fig. 6, the bomb is equipped with a so-called kick-off plugAll connections and components located below this kick-off plug arecontained in the tail member I3 of the bomb. Connections above plug 5|are made on the ship,

plug 5| being at the end of a short length of fourwire cable which pullsthe plug 5| out after the bomb has moved away a few feet. The four wires52, 53, 54, 55 serve certain purposes before ,the bomb is released. Asthe bomb drops away, the connections to these wires are severed andthereafter the bomb operates on its own as a self-contained unit. Wire54 connects directly to the ships ground and serves as an electricalground before release. Wire 55 connects to the customary electrical bombrelease mechanism on the ship and serves to uncage the directional gyroto be described later. An electrical impulse from the release mechanismis imparted at release through wire 55 to perform this function. Wire 53is connected through switch 56 to +24 volt ships power supply, thisconnection serving to supply power to various components of the bombprevious to its release so that all parts will be in operating conditionwhen released. Switch 56 is normally closed a short time before release.Wire 52 connects through switch 51 to the 24 v. ships power and servesthe purpose of arming the tail flare I4 (Fig. 1). This is a safetymechanism to prevent premature operation of the flare. These four wiresare severed at contacts 52', 53', 54' and 55 when the kick-off plugpulls out on release, and thereafter the springs of a kick-oil switchindicated generally'by numeral 58 make other connections as shown.Mechanical interconnections between contact springs are indicated byarms 59 and 68, these being made of insulating material.

Considering now the various components on the bomb itself, these will bedescribed separately. Flare I4 connects through wire 6| to a thermaltrip relay 62. The thermal release 63 is connected by the wire 288 tocontact 52. Movable contact 64 is grounded through wire 65. Wire 6| isthus seen to be open until the bombardier closes flare arming switch 51,whereupon thermal unit 63 burns out, permitting contact 64 to connect towire 6|, grounding one side of the flare. The other connection of theflare made through wire 66 connects through current limiting resistor 61to spring 68 of the kick-off switch. When the kick-off plug pulls out onrelease, spring 88 connects to spring 69 and is thereby connected viawires II and 12 to the 24 v. battery 18 contained in the bomb. Thenegative terminal of battery 18 is grounded on the bomb. Thus thesevering of the kick-off plug closes the above circuit and the batterypower ignites the flare fuse.

A time-delay fuse allows the bomb approximately turn gyro maintained inthe same plane provides a rate-controlling mechanism. These two gyrosproperly coupled cooperate to prevent excessive roll oscillation of thebomb. The gyro unit itself forms the subject'matter of co-pendingapplication Serial No. 543,163 by Molnar and Carnvale and is indicatedgenerally by numeral 13, and will be described in more detail later.Five wires I4, 15, I6, 11, and 18 are connected to the gyro unit. Wire14 connects through spring I9 to contact 55' on the kick-off plug andvia wire 55 to the bomb release mechanism. An electrical impulse fromthe release mechanism is transmitted to wire I4 to uncage the gyro atrelease. In order to make sure that the gyro does uncage properly,spring 19 connects with spring 9I when the kickoff plug is pulled andthis serves to connect wire I8 through spring I9, spring 9|, and wire I2to the bombs battery I8 to effectively actuate the gyro uncagingmechanism.

Wire 15 is seen to connect via wire I68 through current limitingresistor to wire 8| and spring 82, thence through contact 53 and wire 53to the bombardiers warm-up switch 56. Through this circuit thebombardier may, before release, set the gyros in motion. .Subsequent torelease; that is, when connection 53' has been broken, power to wire I5is supplied through wire 83 and spring 88 connecting to spring 85,thence via wire 88 and wire I2 to the battery I8 on the bomb.

One may also note at this point that warm-up switch 56 leading throughwire 53, contact 58', spring 82, wire 8|, and rectifier 81, wire 88,wire 86, wire I2, supplies ships power to maintain the 24 v. battery onthe bomb fully charged.

Wires I6 and I1 from the gyro unit connect via wires 89 and 98 toaileron control solenoids 9| and 92 (shown also as 28, Fig. 2), thedetailed mechanical operation of which has been described in connectionwith Fig. 2. .Wire 18 serves as a ground for the gyro unit. Wire I81serves as ground return forthe aileron control solenoids via springs I88and I89 and wire I I8. Thus until the kick-oil plug has been releasedthe aileron solenoids cannot be energized.

Fig. 7 is a detailed schematic diagram of the gyro unit I3, connectionsI4, I5, I6, 11, and 18 being made to wires of the same number in Fig. 6.After the bomb has been released, connection 14 is made to the positiveterminal of the bombs battery, as previously described thus actuatingthe gyro uncaging solenoid 91. Terminal I5, after release, also connectsto the bombs battery as previously described, thus supplying power tothe gyro motors 93 and 94 through radio-frequency choke 95 and condenserbypass 96 to ground. Choke 95 and condenser 96 serve as a filter toprevent commutator interference with other apparatus on the bomb.

Terminal I4 also supplies power to the center contacts 98 and 99 of arelay whose coil is shown at I88. Contacts 98 and 99 are biased toconnect to springs IM and I82 when coil I88 is not energized. When relayI88 is energized, contacts 98 and 99 connect to springs I83 and I84.Relay I88 is energized from connection 14 and controlled throughcontactors I and I86 mounted on the gyro gimbals in a manner describedin the aforementioned Molnar and Carnvale application. When relay I88 isnot energized, the contact springs 98 and 99 lead to contacts I8I andI82 and battery power from terminal 14 is supplied to terminal 16.Contactors I85 and I86 are so arranged that when the bomb rolls pastneutral in the opposite direction and relay I 88 is ener- 11 gized,contactsprings 08 and 99 supply energy to terminal 11 through contactsI03 and I04. Relay coil I has resistor shunt III to prevent chatteringand the relay contacts have shunts II2 to prevent sparking. The two setsof relay contacts 99 and 99 are provided to handle the aileron solenoidcurrent without heating or sticking.

Returning to Fig. 6, it is seen that wire connects to wire 89 andenergizes counterclockwise solenoid 92, current returning to ground viawire I01, spring I09, spring I09, and wire IIO.

If terminal 11 is energized, wire 11 (Fig. 6) leads through wire 90 andclockwise solenoid coil 9| and to ground through wire I01, spring I08,spring I09, and wire IIO. Thus, it is seen that the gyro unit controlsthe operation of either clockwise aileron solenoid 9I orcounterclockwise aileron solenoid 92.

Details of gyro mechanism I05 and I06 are contained in theaforementioned Molnar and Carnvale application and do not form a part ofthis invention-per se. It is suflicient to point out here that thecontactor I00 coupled to the direction gyro opens the ground connectionto the relay coil I00 on one side of the equilibrium position and closesit on the other. The ailerons are thus always at one extreme position orthe other, producing slight roll of the bomb about the properorientation. This roll is prevented from becoming excessive by theaction of the rate gyro coupled to contactor I05. Contactor I05 opensthe ground connection to relay I00 at a rate-ofroll exceeding about 5-10in one direction, and closes the ground to relay I00 at a, rate-of-rollexceeding the same amount in the other direction (1. e., when contactorI05 is opening). In addition, the direction and rate-oi-roll gyrosdescribed in the above-mentioned Molnar and Carnvale application arecoupled together in such manner that zero position on the direction gyrovaries with displacement of the rate gyro and hence with the rolling ofthe bomb. The efiect of this couping is to permit a speed of rotationproportional to the displacement of the bomb from its equilibriumposition and this materially improves the roll stability attained by thegyro control.

Referring again to Fig. 6, the radio equipment on the bomb is showngenerally by numeral I34 having terminals I to I33. Radio equipment I34comprises a receiver, shown also as 41 in Fig. 5, and four illters shownin Fig. 5 as D, U, L, and R. Radio I34 receives its signals from antennaI38 which is shown also as 46 in Fig.

5 and I5 in Fig. 1. Terminal I20 is connectedto ground through wire I31.The radio receives its power through terminal I21 supplied with 24 v.

power through wires I02 and 83, springs 84 and 85, wires 86 and 12.However, prior to release of the bomb and before the kick-oil plug isreleased, the radio receiver obtains warm-up power through wire I62,resistor 80, wire 8|, spring 82, contact 53', wire 53 to the bombardierswarm-up switch 56. Terminals I28, I 29, and I are connected to therudder actuator while terminals I3I, I32,

and I 33 are connected to the elevator actuator. The actuatorsthemselves will be described in connection with Fig. 9, but the radioequipment serves by means of relays to apply a ground to the appropriateconnection desired. In the absence of a control signal, terminals I29and I32 are grounded and the elevators and rudders return to centerposition. Thus, for right rudder, the radio apparatus grounds terminalI28, at the same time opening the ground on centering terammo mlnal I29.Similarly, for left rudder, terminal I30 is grounded and the ground onI29 is opened.

These connections are accomplished by a relay circuit shown in Fig. 8.

In Fig. 8, numerals II3, I I4, H5, H0 represent the plate connection ofthe last tube of the previously mentioned audio filters D, U, L,'and R,respectively, each 01 these plates being connected through relay coilH1, H8, H9, I20 to a common high potential terminal I2I leading to theradio plate power supply. Armature contact springs I22, I23, I24, I25are normally connected to the right-hand contact. Upon energizing therelay coil, the center spring is drawn over to the lefthand contact. Thediagram (Fig. 8) indicates how the contacts are connected to theterminals I28 to I33, these being the same terminals as those of thesame numbers in Fig. 6. Thus, if

no steering signal is applied, the relays will be in the position shown,and terminal I32 is connected to ground through wire I39, contact I22,wire I40, contact I23, and wires HI and I42. Terminal I 29 is alsoconnected to ground through wire I43, contact I24, wire I44, contactI25, and wire I42. If the bombardier applies a signal of properfrequency to actuate the D (down) filter, relay II1 pulls contact I22 tothe left. This grounds terminal I33 through left contact I22, wire I40,contact I23, wires HI and I42. At the same time the ground on centerconnection I32 is broken at I22. For up elevator, relay II 8 is actuatedand spring I23 drawn to the left, which grounds terminal I3I throughwire I45, left-hand contact I23, wires HI and I42. At the same time theground on center terminal I32 is opened at the right side of I23. Forleft rudder, relay II9 draws contact I24 to the left. This connectsterminal I30 to ground via wire I40, left-hand contact I24, wire I44,contact I 25, and wire I42. At the same time the ground on centerterminal I29 is opened at the right side of I24. For right rudder,terminal I20 is grounded through wire I41, left-hand contact I25, andwire I42, at the same time opening the ground on center terminal I29 atthe right side of I 25. Keeping in mind that the application of steeringsignal merely grounds the appropriate terminal on the rudder or elevatoractuator mechanism, we shall now describe these mechanisms by referenceto Fig. 9.

The rudder and elevator actuating mechanisms are indicated in Fig. 6 bynumerals I and IOI. These mechanisms are both alike and are'energizedwith 24 v. power from the bomb battery through a circuit as follows:wire 12, wire 00, spring 85, spring 84, wire 03, wire I62, wires I03 andI04 to the rudder actuator and I05 to the elevator actuator. A groundconnection is obtained through wires I66, I00 and I31. The other threeterminals on each of the actuating mechanisms go to radio terminals I20to I33 previously referred to. Inasmuch as .both actuating mechanismsare alike, only one will be described in detail,

Fig. 9 is a schematic wiring diagram of one of the actuating mechanismsfor the steering surfaces. The mechanism consists of a shunt wound D.-C.motor whose field is indicated by HI and armature by I50. This motoroperates through a gear trainto rotate arm 31 of Fig. 3. The principleof operation is that when left rudder signal is received, the actuatingmotor moves the rudders to the extreme left position. If no signal isreceived, the actuating motor automatically returns the rudder to thecenter position. Right rudder signal moves the rudder 13 to the extremeright position, etc. To assist in executing these movements, the arm 81of Fig.

. 3 operates through appropriate cams to switches are both open onlyover a very small region at the center position. Contacts I53R and I531.ar closed, respectively, when the arm 31 is off center to the right orleft, respectively. A relay having coil IR, when energized, movescontacts I13 and I14 to the left. Another relay I'IIIL, when energized,moves contacts I'll and I12 to the left. Contacts I1I, I12, I18, I14 arereturned to the right-hand position by springs I when the relay coilsare de-energized. Terminal I64 is' connected to the 24 v. supply;terminal I61 is the ground connection; and terminals I 28, I29, and I30go to the corresponding connections on the radio (see Fig. 6).. Bearingin mind the mechanical operation of switches I52 and I53 and of relaysI10R and I10L, and

.the fact that radio control of Fig. 8 merely grounds the desiredterminal I28, I29, or. I30, we shall now describe the operation of theactuating mechanism of Fig. 9.

We shall assume for example that the rudders are originally in thecenter position so that contacts I53L and R are both open, contacts I52Land R are both closed, such being the situation when no signal isapplied. Upon the application of left rudder signal, the radio relay II8(Fig. 8) will ground terminal I30 (Fig. 9). Current then flows throughthe circuit as follows:

24 v. current enters through wire I64, contacts I52, wire I16, relaycoil I10L, wire I56 to the ground on terminal I30. This pulls contactsHI and I12 to the left and the current flows from wire I64, wire I11,wire I18, contact I13, wire I83, contact I14, wire I18, wire I80downward through motor armature I50, wire I8I, wire I82, contact I12left, wire I83, contact I1I left, wires I84, I55 to ground. At the sametime the current flows from I64 through I11 and I18 to the motor fieldI5I, wire I85 and wire I55 to ground. The motor subsequently rotates topush the rudders to the left until the left limit is reached, whereuponarm 31 (Fig. 2) opens contact I52L, thereby releasing contacts "I andI12 to cut off the motor. The motor will remain in this position as longas left rudder is being applied; namely, as long as terminal I30 is theonly one grounded. If, however, the bombardier ceases to apply leftrudder, then the radio relay (Fig.

8) opens the ground on I30 and automatically applies a ground on I28.The 24 v. power now flows as follows: through wire I64, contact I52R,wire I86, relay I10R, wire I81, wire I88, contact I53L, wire I89, toterminal I29. This energizes relay I10R, moving contacts I13 and I14 tothe left. Current may now flow through the motor armature as' follows:wire I64, wire I11, contact I1I, wire I83, contact I12, wire I90, wireI8I, upward through armature I50, wire I80, wire I82, contact I14 left,wire I93, contact I13 left, wire I85, and wire I55 to ground. Thiscauses right-hand rotation of the motor until the center 14 is reached,whereupon contact I581 opens. This breaks the circuit through relayI10R, releasing contacts I13 and I14 and shutting off the motor. Theapplication of right rudder grounds terminal I28 and removes the groundfrom terminal I28 and the subsequent operation of the device is verysimilar to that when left rudder is applied except that direction ofcurrent flow in the armature is such as to produce right-hand rotation.If, after the application of right rudder, the steering signal isremoved, the motor returns to center in essentially the same manner asabove described. If the bombardier desires to do so, he

. may apply right rudder immediately after the application of leftrudder or vice versa, in which case the motor does not stop at thecenter position but continues to the extreme of whichever position isdesired. In order to eliminate commutator interference, condensers I areconnected across the armature and grounded at their mid-point asindicated. Rectifiers I96 are connected as shown in order to furtherreduce commutator interference. Resistors I81 may be connected acrossrelay coils I10R. and I10L in order to reduce chattering. The elevatoractuating mechanism is identical to that described above except that itsmotor actuates the elevator surfaces instead of rudder surfaces. Sincethe two actuating mechanisms are entirely independent. the bombardiermay, if he desires, apply both rudder and elevator controlsimultaneously.

Having thus described our invention and its operating details it isapparent that various changes and modification may be made by oneskilled in the art. Thus, while we have shown a simple form of On-Oficontrol, both in the control of the ailerons and the rudders andelevators, a proportional type of control may be used as well. Otherforms of control surfaces may be employed within the scope of ourinvention. Furthermore, our invention may be used with any type ofdirigible bomb and may be used for bombing moving as well asstationarytargets.

What we claim as our invention is:

1. A dirigible missile comprising a war head, a unitary tail structure,a substantially cylindrical aerodynamic control surface fixedly mountedon said tail structure, radial supports which attach said controlsurface to the tail structure, aerodynamic steering surfaces operablymounted on the trailing edge of said cylindrical control surface, meanscontained in said tail structure operating one alternate pair ofsteering surfaces as rudders which place the missile into an attitude ofyaw so that the associated control surface may produce forcesdeflecting' the path of the missile, means contained in said tailstructure operating the other alternate pair of steering surfaces aselevators which place the missile in an attitude of pitch so that theassociated control surface may produce forces deflecting the path of themissile, a radio antenna mounted or said tail structure and connected tomeans contained in said tail structure receiving and transducing a radiosignal, means contained in said tail structure controlling said rudderoperating means and said elevator operating means in response to thecharacter of the radio signal received, ailerons operably mounted on thetrailing edge of said radial supports, means contained in said tailstructure operating said ailerons in unison tending to axially rotatethe missile, and gyroscopicmeans contained in said tail structurecontrolling said aileron operating means so that resulting aileronaction maintains the missiles rotational orientation such that therudder and elevator hinge axes lie in vertical and horizontal planesrespectively.

2. A dirigible missile comprising a war head, a unitary tail structure,two substantially cylindrical aerodynamic control surfaces fixedlymounted on said tail structure, staggered radial supports which attachsaid control surfaces to the tail structure, aerodynamic steeringsurfaces operably mounted on the trailing edge of one of saidcylindrical control surfaces, means contained in said tail structureoperating one alternate pair of steering surfaces as rudders which placethe missile into an attitude of yaw so that the associatedcontrolsurface may produce forces deflecting the path of the missile,means contained in said tail structure operating the other alternatepair of steering surfaces as elevators which place the missile in anattitude of pitch,so that the associated control surface may produceforces deflecting the path of the missile, a radio antenna mounted onsaid tail structure and connected to means contained in said tailstructure receiving and transducing a radio signal, means contained insaid tail structure controlling the rudder operating means and theelevator operating means in response to the character of the radiosignal received, ailerons operably mounted on the trailing edge ofdiametrically opposite radial supports, said ailerons being mounted ontorque rods having a bifurcated crank arm on their inner extremity, anaxially pivoted plate having radial pins engaging the bifurcation ofeach aileron crank arm, solenoid means rotating said pivoted plate,gyroscopic means contained in said tail structure controlling saidaileron operating solenoids so that resulting aileron action maintainsthe missiles rotational orientation such that the rudder and elevatorhinge axes lie in vertical and horizontal planes respectively, a flaremaking visible the missile in its path, and means for igniting the flareand initiating operation of the aforesaid control means on release ofthe missile.

3. A dirigible missile comprising a war head, a unitary tail structure,substantially cylindrical aerodynamic control surfaces fixedly mountedon said tail structure, radial supports which attach said controlsurface to the tail structure, aerodynamic steering surfaces operablymounted on the trailing edge of said cylindrical control surface, meanscontained in said tail structure operating one alternate pair ofsteering surfaces as rudders which place the missile into an attitude ofyaw so that the associated control surface may produce forces deflectingthe path of the missile, means contained in said tail structureoperating the other alternate pair of steering surfaces as elevatorswhich place the missile in an attitude of pitch so that the associatedcontrol surface may produce forces deflecting the path of the missile, aradio antenna mounted on said tail structure, means contained in saidtail structure receiving and transducing a radio signal, means containedin said tail structure controlling the rudder operating means in suchmanner that the rudders are urged into their extreme steering positionsin response to a selected frecuency of modulation of the received radiosignal. means contained in said tail structure controlling the elevatoroperating means in such manner that the elevators are urged into theirextreme steering position in response to a different selected frequencyof modulation of the received radio signal, ailerons operably mounted on16 the trailing edge of diametrically opposite radial supports, meanscontained in said tail structure operating said ailerons in unisontending to axially rotate the missile, and gyroscopic means contained insaid tail structure controlling said ail-- eron operating means so thatresulting aileron action maintains the missiles rotational orientationsuch that the rudder and elevator hinge axes lie in vertical andhorizontal planes respectively.

4. A dirigible missile comprising a war head, a unitary tail structure,a substantially prismatic aerodynamic control surface fixedly mounted onsaid tail structure, a substantially prismatic aerodynamic controlsurface removably mounted on said tail surface at alocation such thatthe missile remains stable on removal thereof, staggered radial supportswhich attach said control surfaces to the tail structure, aerodynamicsteering surfaces operably mounted on a straight portion of the trailingedge of said fixed prismatic control surfaces, means contained in saidtail structure operating one alternate pair of steering surfaces asrudders which place the missile into an attitude of yaw so that theassociated control surface may produce forces deflecting the path of themissile, means contained in said tail structure operating the otheralternate pair of steering surfaces as elevators which place the missilein an attitude of pitch so that the associated control surface mayproduce forces deflecting the path of the missile, a radio antennamounted on said tail structure and connected to means contained in saidtail structure receiving and transducing a radio signal, means containedin said tail structure controlling the rudder operating means and theelevator operating means in response to the character of the'radiosignal received, ailerons operably mounted on the trailing edge of saidradial supports, means contained in said tail structure operating saidailerons in unison tending to axially rotate the missile,gyroscopicmeans contained in said tail structure controlling saidaileron operating means so that resulting aileron action maintains themissiles rotational orientation such that the rudder and elevator hingeaxes lie in vertical and horizontal planes respectively.

5. A dirigible missile comprising a war head, a unitary tail structure,a substantially cylindrical aerodynamic control surface fixedly mountedon said tail structure, said control surface being dimensioned to impartto the missile a period of oscillation of from 0.3 to 2 seconds, radialsupports which attach said control surface to the tail structure,aerodynamic steering surfaces operably mounted on the trailing edge ofsaid cylindrical control surface, means contained in said tail structureoperating one alternate pair of steering surfaces as rudders which placethe missile into an attitude of yaw so that the associated controlsurface may produce forces deflecting the path of the missile, meanscontained in said tail structure operating the other alternate pair ofsteering surfaces as elevators which place the missile in an attitude ofpitch so that the associated control surface may produce forcesdefleeting the path of the missile, a radio antenna mounted on said tailstructure and connected to means contained in said tail structurereceiving and transducing a radio signal, means contained in said tailstructure controlling the rudder operating means and the elevatoroperating means in response to the character of the radio signalreceived, ailerons operably mounted on the trailing edge of said radialsupports, means contained in said tail structure, said control surfacebeing dimensioned to impart a lift coefilcient at maximum trim of from0.4 to 2.0, radial supports which attach said control surface to thetall structure, aerodynamic steering surfaces operably mounted on thetrailing edge of said cylindrical control surface, means contained insaid tail structure operating one alternate pairof steering surfaces asrudders which place the missile into an attitude of yaw so that theassociated control surface may produce forces deflecting the path of themissile, means contained in said tail structure operating the otheralternate pair of steering surfaces as elevators which place the missilein an attitude of pitch so that the associated control surface mayproduce forces deflecting the path of the missile, a radio antennamounted on said tail structure and connected to means contained insaidtail structure receiving and transducing a radio signal, meanscontained in said tail structure controlling the rudder operating meansand the elevator operating means in response to the character of theradio signal received, ailerons-operably mounted on the trailing edge ofsaid radial supports, means contained in said tail structure'operatin gsaid ailerons in unison tending to axially rotate the missile andgyroscopic means contained in said tail structure controlling saidaileron operating means so that resulting ailer'on action maintains themissiles rotational orientation such that the rudder and elevator hingeaxes lie in vertical and horizontal planes respectively.

7. A dirigible missile comprising a war head, a unitary tail structure,a substantially cylindrical aerodynamic control surface fixedly mountedon said tail structure, said control surface having a length less than30 per cent of the total length of the missile, radial supports whichattach said control surfaces to the tail structure, aerodynamic steeringsurfaces operably mounted on the trailing edge of said cylindricalcontrol surface, means contained in said tail structure operating onealternate pair of steering surfaces as rudders which place the missileinto an attitude of yaw so that the associated control surface mayproduce forces deflecting the path of the missile, means contained insaid tail structure operating the other alternate pair of steeringsurfaces as elevators which place the missile in an attitude of pitch sothat the associated control surface may produce forces deflecting thepath of the missile. a radio antenna mounted on said tail structure andcormected to means contained in said tail structure receiving, andtransducing a radio signal, means contained in said tail structurecontrolling the rudder operating means and the elevator operating meansin response to the character of the radio signal received, ailerons oerably mounted on the trailing edge of said radial supports, meanscontained in said tail strrcture operating said ailerons in unisontending to axially rotate the missile, and gyroscopic means contained insaid tail structure controlling said aileron operating means so thatresulting aileron action maintains the missiles rotational orientationsuch that the rudder and elevator hinge axes lie in vertical andhorizontal planes respectively.

8. A dirigible missile comprising a war head, a unitary tail structure,two substantially cylindrical aerodynamic control surfaces fixedlymounted on said tail structure, the sum of the chord lengths of saidcontrol surfaces being less than 50 per cent of the total length of themissile, radial supports which attach said control surfaces to the tailstructure, aerodynamic steering surfaces operably mounted on thetrailing edge of said cylindrical control surface, means contained insaid tail structure operating one alternate pair of steering surfaces asrudders which place the missile into an attitude of yaw so that theassociated control surface may produce forces deflecting the path of themissile, means contained in said tail structure operating the otheralternate pair of steering surfaces as elevators which place the missilein an attitude of pitch so that the associated control surface mayproduce forces deflecting the path. of the missile, a radio antennamounted on said tail structure and means contained in said tailstructure receiving and transducing a radio signal, means contained insaid tail structure controlling the rudder operating means and theelevator operating means in response to the character of the radiosignal received, ailerons operably mounted on the trailing edge of saidradial supports, means contained in said tail structure operating saidailerons in unison tending to axially rotate the missile, and gyroscopicmeans contained in said tail structure controlling said aileronoperating means so that resulting aileron action maintains the missilesrotational orientation such that the rudder and elevator hinge axes liein vertical and horizontal planes respectively.

9. A dirigible missile comprising a war head, a unitary tail structure,two substantially cylindrical aerodynamic control surfaces fixedlymounted on said tail structure, said control surfaces being separated bya distance greater than 10 per cent of the chord length of the smallersurface, radial supports which attach said control surfaces to the tailstructure, aerodynamic steering surfaces operably mounted on thetrailing edge of said cylindrical control surface, means contained insaid tail structure operating one alternate pair of steering surfaces asrudders which place the missile into an attitude of yaw so that theassociated control surface may produce forces deflecting the path of themissile, means contained in said tail structure operating the otheralternate pair of steering surfaces as elevators which place the missilein an attitude of pitch so that the associated control surface mayproduce forces deflecting the path of the missile, a radio antennamounted on said, tail structure and connected to means contained in saidtafl structure receiving and transducing a radio signal, means containedin said tail structure controlling the rudder operating means and theelevator operating means in response to the character of the radiosignal received, ailerons operably mounted on the trailing edge of saidradial supports, means contained in said tail structure operating saidailerons in unison tending to axially rotate the missile, and gyroscopicmeans contained in said tail structure controlling said aileronoperating means so that resulting aileron action maintains the missilesrotational orientation such that the l9 rudder and elevator hinge axeslie in vertical and horizontal planes respectively.

10. A dirigible missile comprising a war head, a unitary tail structure,a substantially cylindrical aerodynamic control shroud ilxedly mountedon said tail structure, radial supports which attach said control shroudto the tail structure, aerodynamic steering flaps operably mounted onthe trailing edge of said cylindrical control shroud, said steeringflaps being dimensioned so that the total flap area in per cent of totalshroud area multiplied by the maximum available flap deflection indegrees lies between 35 and 325, means contained in said tail structureoperating one alternate pair of steering surfaces as rudders which placethe missile into an attitude of yaw so that the associated controlsurface may produce forces deflecting the path of the missile, meanscontained in said tail structure operating the other alternate pair ofsteering surfaces as elevators which place the missile in an attitude ofpitch so that the associated control surface may produce forcesdeflecting the path of the missile, a radio antenna mounted on said tailstructure and connected to means contained in said tail structurereceiving and transducing a radio signal, means contained in said tailstructure controlling the rudder operating means and the elevatoroperating means in response to the character of the radio signalreceived, ailerons operably mounted on the trailing edge of said radialsupports, means contained in said tail structure operating said aileronsin unison tending to axially rotate the missile, and gyroscopic meanscontained in said tail structure controlling said aileron operatingmeans so that resulting aileron action maintains the missile'srotational orientation such that the rudder and elevator hinge axes liein vertical and horizontal planes respectively.

11. A dirigible missile comprising a war head, a unitary tail structure,a substantially cylindrical aerodynamic control shroud fixedly mountedon said tail structure, radial supports which attach said control shroudto the tail structure, c steering surfaces operably mounted aaoamshroud, means contained in said tail structure operating one alternatepair of steering surfaces as rudders which place the missile intoanattitude of yaw so that the associated control surface may produceforces deflecting the path oi the missile, means contained in said tailstructure operating the other alternate pair of steering surfaces aselevators which place the missile in an attitude of pitch so that theassociated control surface may produce forces deflecting the path of themissile. a radio antenna mounted on said tail structure and connected tomeans contained in said tail structure receiving and transducing a radiosignal, means contained in said tail structure controlling the rudderoperating means and the elevator operating means in response to thecharacter of the radio signal received, ailerons operably mounted on thetrailing edge of said radial supports, said ailerons being dimensionedso that the total moving area thereof in per cent of the total shroudarea multiplied by the maximum aileron deflection in degrees liesbetween 20 and 200, means contained in said tall structure operatingsaid ailerons in unison, andgyroscopic means contained in said tailstructure controlling said aileron operating means so that resultingaileron action maintains the missile's rotational orientation such thatthe rudder and elevator hinge axes lie in vertical and horizontal planesrespectively.

RALPH D. WYCKOFF. JAMES W. FITZWILLIAM. DANTE SALVE'ITI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,537,713 Sperry May 12, 19252,404,942 Bedford July 30, 1946 2,414,898 Rous Jan. 28, 1947 2,425,558Ohlendorf Aug. 12, 1947 20 v on the trailing. edge of ma cylindricalcontrol

